JP2009268196A - Brushless motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brushless motor positioning a drive coil directly onto a circuit board. <P>SOLUTION: In the brushless motor, a flat vibration motor includes a stator 10, which has a power supply flexible board 13 provided with drive air core coils C<SB>1</SB>to C<SB>4</SB>on a stator plate 11 in which a supporting shaft 12 is planted, and a rotor, which has an annular magnet facing the drive air core coils C<SB>1</SB>to C<SB>4</SB>and is supported rotatably by the supporting shaft 12 via a metal bearing. The motor further includes a coil-positioning annular plate 19 made of a resin, which the supporting shaft 12 passes through and is positioned by being fitted into a locking hole 13a of the power supply flexible board 13. The top face level of the coil-positioning annular plate 19 is positioned between the top face of the power supply flexible board 13 and the top end faces of the drive air core coils C<SB>1</SB>to C<SB>4</SB>. The coil-positioning annular plate 19 has stopper parts W<SB>1</SB>to W<SB>4</SB>, which determine the position of the drive air core coils C<SB>1</SB>to C<SB>4</SB>by contacting shaft side protruding surfaces X<SB>1</SB>to X<SB>4</SB>of the drive air core coils C<SB>1</SB>to C<SB>4</SB>at its outside circumference side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a brushless motor applicable to a vibration motor or the like.

In Japanese Patent Application Laid-Open No. 2003-111374, a silicon steel plate (magnetic plate), a flexible wiring board, a stator in which a plurality of drive coils are laminated and fixed on a base member, and a magnet that faces the drive coil are rotatably provided on the base member. A brushless motor is shown having a supported shaft and a integrally rotating rotor.
Japanese Patent Laid-Open No. 2003-111374 (FIGS. 1 and 3)

  Conventionally, the assembly operation for fixing the drive coil on the flexible wiring board has an outer diameter of several millimeters. Therefore, a plurality of drive coils are temporarily set on the positioning portion of the jig and the drive coil is fixed. After the adhesive is applied to the end face, the jig is turned upside down and the drive coil is positioned and fixed to the flexible wiring board. Since this is an assembly operation using the jig, the work efficiency is inferior.

  In view of the above problems, an object of the present invention is to provide a brushless motor having a stator capable of directly positioning a drive coil on a circuit board.

  The present invention includes a stator having a circuit board on which a plurality of drive coils are mounted on a stator plate in which a support shaft is implanted, a magnet that faces the drive coil, and is rotatably supported by a support shaft via a bearing. A brushless motor having a rotor and a resin-made annular member that is positioned by being fitted in a rotation-preventing hole of the circuit board, and the upper surface level of the annular member is between the upper surface of the circuit board and the upper end surface of the drive coil. The annular member is located between them, and has a stopper portion for positioning the drive coil by abutting the outer peripheral surface of the drive coil on the outer peripheral side thereof.

  In assembling the stator, the circuit board is arranged on the stator plate, and an annular member is fitted into the rotation stop hole for positioning, and then the outer peripheral surface of the drive coil is brought into contact with the stop portion of the annular member. Since the coil can be positioned, the working efficiency can be improved. Further, since the positioning of the annular member itself is realized by the non-rotating hole of the circuit board, the positioning of the drive coil can be achieved on the basis of the circuit board on which they are mounted, and the number of components does not increase. Since the upper surface level of the annular member is located between the upper surface of the circuit board and the upper end surface of the drive coil, the thickness of the stator can be kept as before.

  As the stopper for performing the positioning function, for example, a plurality of protrusions may be integrally provided on the outer peripheral side of the annular member for each drive coil. In order to achieve this, it is desirable that the outer peripheral surface of the drive coil be a concave wall that engages with the axial convex surface facing the spindle. This is because if the position of the drive coil is finely adjusted so that the shaft-side convex surface is correctly aligned with the concave wall, positioning with respect to the center can be naturally realized.

  The concave wall may protrude between adjacent drive coils on the circuit board as long as there is enough space, but in order to increase positioning accuracy while ensuring a long concave wall, it is within the range of the detent hole. Is desirable. However, conversely, since the convex portion of the drive coil protrudes from the circuit board into the anti-rotation hole, a problem remains in the electrical insulation reliability of the convex portion.

  Therefore, it is desirable that the annular member has an overhanging base portion that receives the lower end surface of the drive coil at a surface level equal to the upper surface of the circuit board on the concave wall. Since the lower surface of the convex portion of the drive coil is covered with the projecting base portion of the annular member instead of the circuit board, electrical insulation can be ensured.

  The annular member may have a washer receiving hole in which a washer through the support shaft is loosely fitted. When the washer receiving hole is a through hole, for example, a bottom raising washer and a rotating washer are loosely fitted. In the case of a stepped hole formed with a diameter larger than the shaft hole through which the support shaft passes on the upper surface side of the annular member, it is only necessary to loosely fit the rotating washer, and the support shaft only needs to be press-fitted into the shaft hole. The stepped hole can form a lubricating oil reservoir that can supply oil to the washer.

  The driving coil is preferably an air-core coil, and an adhesive is injected into the air-core portion and the air-core coil is fixed to the circuit board.

  When the circuit board is a flexible wiring board, the board thickness can be reduced. The brushless motor can be applied to a vibration motor having an eccentric weight in the rotor.

  According to the present invention, a brushless motor capable of directly positioning a drive coil on a circuit board can be provided.

  Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

  1 is a longitudinal sectional view showing a flat vibration motor according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a stator of the flat vibration motor, FIG. 3 is an assembled perspective view of the stator, and FIG. FIG. 5A is a plan view showing a coil positioning annular plate used for the stator, and FIG. 5B is a line bb ′ in FIG. 5A. It is sectional drawing cut | disconnected along the line.

  The flat type (coin type) vibration motor of this example is a brushless motor including a stator 10 and a rotor 20 as shown in FIG. The stator 10 includes a stator plate (base plate or bottom plate) 11 made of a circular magnetic material (silicon steel plate), a support shaft 12 whose one end is press-fitted into a central hole 11a of the stator plate 11 and fixed by welding, and a stator plate 11 The flexible wiring board 13 for power feeding, which is positioned on the upper surface and bonded by fusion, the resin washers 14 and 15 loosely fitted to the support shaft 12, and the other end of the support shaft 12 are press-fitted and the lower opening is the stator plate 11 And a cup-shaped housing 16 closed by the

The stator plate 11 has three cogging generating round holes 11 b for avoiding the dead point of the rotor 20. As shown in FIGS. 2 to 4, the power supply flexible wiring board 13 has a D-shaped detent hole 13a through which the support shaft 12 passes at the center, and is arranged at equal intervals of 45 ° around the detent hole 13a. The four drive air-core coils C ₁ , C ₂ , C ₃ , C ₄ and the hall elements that are arranged in the vicinity of the straight edge S of the hole edge of the anti-rotation hole 13a and that detect magnetism are built in and drive coils C ₁ -C _{4 is} mounted with a drive control IC 17 for switching the excitation current to ₄ to form a rotating magnetic field, and a capacitor 18 arranged outside the drive control IC 17.

As shown in FIG. 5, a non-circular coil positioning annular plate 19 having a washer receiving hole 19a is fitted and positioned in the rotation stop hole 13a. The positioning annular plate 19 is made of resin, and on the outer peripheral side thereof, the flat wall F joined to the straight edge S and the outer peripheral surfaces of the driving air core coils C _{1 to} C ₄ are brought into contact with each other so that the driving air coil C ₁ and a contact stop portion _W 1 to _W-4 for positioning the -C _4. The contact stoppers W _{1 to} W ₄ correspond to those obtained by cutting out an arc that matches the hole edge of the rotation stop hole 13 a, and the shaft-side convex surface facing the support shaft 12 among the outer peripheral surfaces of the drive air core coils C _{1 to} C _4. X _{1 to} X ₄ are concave walls that fit together shallowly. The upper end surfaces of the stoppers W _{1 to} W ₄ protrude upward from the upper surface of the power supply flexible wiring board 13, but do not protrude upward from the upper end surfaces of the drive air-core coils C _{1 to} C ₄ . Adhesive in the air-core portion of the drive air-core coil C ₁ -C ₄ (not shown) is injected, the driving air-core coil C ₁ -C ₄ are fixed to the power supply flexible wiring board 13.

The rotor 20 is rotatably supported by the shaft 12 via a metal bearing 21 of the bearing holder portion 23a, with a driving coil _{C 1, C 2, C 3} , C 4 and the surface facing the annular magnet 22 on the lower side A rotor plate (yoke) 23 and an arc-shaped eccentric weight 24 provided on the outer peripheral side of the rotor plate 23 are provided.

In the assembly work of the stator 10, the power supply flexible wiring board 13 is arranged on the stator plate 11, and the coil positioning annular plate 19 is fitted into the rotation stop hole 13 a for positioning. because it can position the driving air-core coil _C 1 -C ₄ by Intention a contact stop portion _W 1 shaft side convex surface _X 1 to X ₄ of the to _W-4 driven air-core coil _C 1 -C ₄ is brought into contact, work efficiency Improvements can be made. Further, since the coil positioning the annular plate 19 itself of the positioning is realized by detent holes 13a of the feeding flexible wiring board 13, power supply flexible wiring positioning drive air-core coil C ₁ -C ₄ are mounted them This can be achieved based on the substrate 13 standard. And since the upper surface level of the coil positioning annular plate 19 does not protrude upward from the upper end surfaces of the driving air-core coils C _{1 to} C ₄ , the thickness of the stator 10 can be kept as before.

For particular abutting stopping part W ₁ to _W-4 of the present embodiment is concave wall, if fine adjustment of the position of the drive coil such that the axial side convex surface X ₁ to X ₄ fits correctly concave wall, also positioned with respect to naturally center realized it can.

  6A is a plan view showing a stator of a flat vibration motor according to a second embodiment of the present invention, and FIG. 6B is a cross-sectional view taken along the line bb ′ in FIG. 6A. 7 is an assembled perspective view of the stator, FIG. 8A is a plan view showing an annular plate for coil positioning used in the stator, and FIG. 8B is a line bb ′ in FIG. 8A. It is sectional drawing cut | disconnected along. 6 to 8, the same parts as those shown in FIGS. 1 to 5 are denoted by the same reference numerals, and the description thereof is omitted.

  This embodiment is different from the first embodiment in the configuration of the coil positioning annular plate 39 in the starter 10 '. The washer-accommodating hole 19a of the first embodiment is a through hole that accommodates the resin washer 14 for raising the bottom and the resin washer 15 for rotation, but the support shaft 12 is press-fitted into the washer-accommodating hole 39a of this example. A large diameter stepped hole H is formed between the shaft hole h and the upper portion. For this reason, it is not necessary to use the resin washer 14 for raising the bottom, and it is sufficient to fit only the surrounding resin washer 15 into the stepped hole H. The stepped hole H can be used as a lubricating oil reservoir for supplying oil to the surrounding resin washer 15, and sliding loss can be reduced.

  9A is a plan view showing a stator of a flat vibration motor according to Embodiment 3 of the present invention, and FIG. 9B is a cross-sectional view taken along the line bb ′ in FIG. 9A. 10A is a plan view showing an annular plate for coil positioning used in the stator, and FIG. 10B is a cross-sectional view taken along the line bb ′ in FIG. 10A. 9 and 10, the same parts as those shown in FIGS. 6 to 8 are designated by the same reference numerals, and the description thereof is omitted.

This embodiment differs from the first and second embodiments in the configuration of the coil positioning annular plate 49 in the stator 10 ″, which is an improvement of the coil positioning annular plate 39 of the second embodiment. In the positioning annular plate 39, the shaft-side convex surfaces X _{1 to} X ₄ of the driving air-core coils C _{1 to} C ₄ protrude from the power supply flexible substrate 13 to the rotation stop hole 13 a, so that the electrical insulation reliability of the protruding portion Sex matters.

Therefore, the coil positioning annular plate 49 of the present example receives the lower end surface of the drive air-core coils C _{1 to} C _{4 at} the same level as the upper surface of the power supply flexible substrate 13 in the stoppers W _{1 to} W ₄ . integrally has a M ₁ ~M _4. Since the vicinity of the shaft-side convex surfaces X _{1 to} X ₄ is covered with the overhanging portions M _{1 to} M ₄ , electrical insulation can be ensured.

It is a longitudinal cross-sectional view which shows the flat vibration motor which concerns on Example 1 of this invention. It is a perspective view which shows the stator of the same flat vibration motor. It is an assembly perspective view of the stator. It is a top view which shows the flexible wiring board for electric power feeding used for the stator. (A) is a top view which shows the annular plate for coil positioning used for the stator, (B) is sectional drawing cut | disconnected along the bb 'line in (A). (A) is a top view which shows the stator of the flat vibration motor which concerns on Example 2 of this invention, (B) is sectional drawing cut | disconnected along the bb 'line in (A). It is an assembly perspective view of the stator. (A) is a top view which shows the annular plate for coil positioning used for the stator, (B) is sectional drawing cut | disconnected along the bb 'line in (A). (A) is a top view which shows the stator of the flat vibration motor which concerns on Example 3 of this invention, (B) is sectional drawing cut | disconnected along the bb 'line in (A). (A) is a top view which shows the annular plate for coil positioning used for the stator, (B) is sectional drawing cut | disconnected along the bb 'line in (A).

Explanation of symbols

10, 10 ', 10 "... Stator 11 ... Stator plate 11a ... Central hole 11b ... Round hole 12 for cogging generation ... Support shaft 13 ... Flexible wiring board 13a for power feeding ... Anti-rotation holes 14, 15 ... Resin washer 16 ... Housing 17 ... Drive control IC
18 ... capacitors 19,39,49 ... coil positioning the annular plate 19a, 39a ... washer accommodation holes 20 ... rotor 21 ... metal bearing 22 ... ring magnet 23 ... rotor plate 23a ... bearing holder portion 24 ... eccentric weight _C 1, _{C 2} , C ₃ , C ₄ ... drive air-core coil F ... flat wall H ... stepped hole h ... shaft hole M _{1 to} M ₄ ... overhang base part S ... linear edge W _{1 to} W ₄ ... hitting stop part X _{1 to} X ₄ ... Axial convex surface

Claims (9)

A stator having a circuit board on which a plurality of drive coils are mounted on a stator plate in which a support shaft is implanted, and a rotor having a magnet facing the drive coil and rotatably supported on the support shaft via a bearing And
It has a resin-made annular member that passes through the support shaft and is positioned by being fitted in a non-rotating hole of the circuit board, and the upper surface level of the annular member is between the upper surface of the circuit board and the upper end surface of the drive coil. The brushless motor is characterized in that the annular member has a stopper portion for positioning the drive coil by contacting the outer peripheral surface of the drive coil on the outer peripheral side thereof. 2. The brushless motor according to claim 1, wherein the stopper portion is a concave wall that engages with an axial convex surface of the outer peripheral surface of the drive coil. 3. The brushless motor according to claim 2, wherein the concave wall is located within the range of the rotation stop hole. 4. The brushless motor according to claim 3, wherein the annular member has a projecting base portion that receives a lower end surface of the drive coil at a surface level equal to an upper surface of the circuit board on the concave wall. 5. The brushless motor according to claim 1, wherein the annular member has a washer receiving hole in which a washer passing through the support shaft is loosely fitted. 6. The brushless motor according to claim 5, wherein the washer receiving hole is a stepped hole formed on the upper surface side with a diameter larger than that of the shaft hole through which the support shaft passes. 7. The brushless motor according to claim 1, wherein the drive coil is an air-core coil, and an adhesive is injected into the air-core portion to fix the air-core coil to the circuit board. A brushless motor characterized by that. The brushless motor according to any one of claims 1 to 7, wherein the circuit board is a flexible wiring board. The brushless motor according to any one of claims 1 to 8, wherein the rotor has an eccentric weight.

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